Biomechanics for inclusive urban design : effects of tactile paving on older adults’ gait when crossing the street

In light of our ageing population it is important that the urban environment is easily accessible and hence supports older adults’ independence. Tactile ‘blister’ paving was originally designed to provide guidance for visually impaired people at pedestrian crossings. However, as research links irregular surfaces to falls in older adults, such paving may have an adverse effect on older people. We investigated the effects of tactile paving on older adults’ gait in a scenario closely resembling “crossing the street”. Gait analysis of 32 healthy older adults showed that tactile, as compared to smooth, paving increases the variability in timing of foot placement by 20%, thereby indicating a disturbance of the rhythmic gait pattern. Moreover, toe-clearance during the swing phase increased by 7% on tactile paving, and the ability to stop upon cue from the traffic light was compromised. These results need to be viewed under consideration of the limitations associated with laboratory studies and real world analysis is needed to fully understand their implications for urban design

Effects of shoe sole geometry on toe clearance and walking stability in older adults

Thirty-five percent of people above age 65 fall each year, and half of their falls are associated with tripping: tripping, an apparently ‘mundane’ everyday problem, therefore significantly impacts on older people's health and associated medical costs. To avoid tripping and subsequent falling, sufficient toe clearance during the swing phase is crucial. We previously found that a rocker-shaped shoe sole enhances toe clearance in young adults, thereby decreasing their trip-risk. This study investigates whether such sole design also enhances older adults’ toe clearance, without inadvertently affecting their walking stability. Toe clearance and its variability are reported together with measures of walking stability for twelve older adults, walking in shoes with rocker angles of 10°, 15°, and 20° degrees. Surface inclinations (flat, incline, decline) were chosen to reflect a potential real-world environment. Toe clearance increased substantially from the 10° to the 15° degree rocker angle (p = 0.003) without compromising measures of walking stability (p > 0.05). A further increase in rocker angle to 20° degrees resulted in less substantial enhancement of toe clearance and came at the cost of a decrease in gait speed on the decline. The novelty of this investigation lies in the exploration of the trade-off between reduction of trip- risk through footwear design and adverse effects on walking stability on real-life relevant surfaces. A large amount of slip-resistant footwear is already available; our two studies highlight that footwear may also be designed to reduce trip-risk